How to connect a second modem to the main one via Wi-Fi: 3 working methods + setup

Want to expand your Wi-Fi coverage but don't know how to properly connect a second modem to your existing one? There are three main ways to accomplish this: bridge mode (WDS), signal repeater or cascade connection via cableEach method has its own nuances, and the choice depends on your goals: whether you simply need to boost the signal in a distant corner of the apartment or set up a separate network for guests with a different username and password.

Many users mistakenly believe that simply connecting two routers with a LAN cable will make everything work. In practice, this is fraught with problems. IP address conflicts, double NAT, and problems accessing local devices. In this article, we'll discuss step-by-step instructions for popular models (TP-Link Archer C6, D-Link DIR-615, Keenetic Giga), we'll explain how to avoid common mistakes and show you what settings need to be changed on both devices.

Important: Before you start setting up, check if your main modem supports the function WDS or bridge mode. Obsolete models (eg. D-Link DIR-300 B1 revisions may not have this option. If the web interface doesn't have a "WDS" or "Bridge" option, you'll have to use alternative methods.

1. Method 1: Connecting via Bridge Mode (WDS)

Mode WDS (Wireless Distribution System) This method allows you to connect two modems wirelessly over the air, maintaining a single network. The main advantage is that the devices will automatically switch between access points if the signal from one modem weakens. However, this method has its drawbacks:

• 🔄 Decrease in speed up to 50% due to traffic retransmission.
• 🔒 Not all models support WPA3 encryption in WDS mode (usually only WPA2-PSK works).
• 📡 Both modems must work on the same frequency (2.4 GHz or 5 GHz).

To set this up you will need:

1. The main modem with Wi-Fi enabled (let's call it Router1).
2. Second modem (Router2), which will operate in bridge mode.
3. A computer or smartphone to access the web interface.

Step 1. Connect to Router1 and write down its parameters:

• Network Name (SSID) - For example, MyWiFi_2.4G.
• Security type - WPA2-PSK or WPA/WPA2.
• Wi-Fi password.
• Channel (Channel) - if it's worth it Auto, fix it manually (for example, channel 6).

Step 2. Set up Router2 in WDS mode:

1. Connect to it via cable or via its own Wi-Fi network (if active).
2. Open the web interface (usually at 192.168.0.1 or 192.168.1.1).
3. Go to the section Wireless Mode → WDS (on TP-Link) or Wi-Fi → Bridge (on Keenetic).
4. Activate WDS mode and enter the data Router1 (SSID, security type, password).
5. In the settings DHCP turn off the server (to avoid IP conflicts).
6. Save the settings and reboot both devices.

Disconnect the cable from Router2|Connect to its Wi-Fi (the name should be the same as Router1)|Check internet access|Make sure the IP address is assigned by Router1 (e.g. 192.168.1.x)|Try moving between coverage areas-->

⚠️ Attention: If after setting up the device it does not receive an IP address, check that Router2 DHCP and its local IP are disabled (for example, 192.168.0.2) does not conflict with the range Router1 (For example, 192.168.1.100-200).

2. Method 2: Using the second modem as a repeater

If your second modem supports the mode repeaterThis simplifies the task. Unlike WDS, there's no need to manually configure channels and encryption types—just select the network to replicate. However, this method has its limitations:

• 🔌 Not all models can work in repeater mode (for example, Zyxel Keenetic requires firmware NDMS 3.0+).
• 📶 The repeater network name will be different (e.g. MyWiFi_EXT).
• 🔄 Speed ​​is also reduced due to retransmission.

Instructions for TP-Link (firmware based on OpenWRT or standard):

1. Connect to the web interface of the second modem.
2. Go to Additional settings → Operating mode.
3. Select Signal amplifier (Repeater).
4. Click "Search" and select the network Router1 from the list.
5. Enter the password for the main network and save the settings.

For Keenetic the path will be different:

Menu → Wi-Fi → Access Point → Range Extender Mode

⚠️ Attention: In repeater mode, the second modem will not be able to distribute the Internet via cable (the LAN port will become inactive) On most budget models. If you need to connect devices via wire, use WDS or a cascade connection.

3. Method 3: Cascaded connection via cable (LAN-to-LAN)

The most stable method is to connect the modems network cableThis guarantees maximum speed and no signal loss. The downside is the need to run a cable between devices. But you'll get:

• 🚀 Full internet speed without loss.
• 🔧 Possibility to create separate subnet (for example, for smart home or guest access).
• 🔌 Active LAN ports on both modems.

Connection diagram:

1. Connect LAN port Router1 With Router2 WAN port (if separate DHCP is needed).
2. Or connect LAN port Router1 With LAN port of Router2 (if you need to expand one network).

Setting up Router2 (using an example) D-Link DIR-615):

1. Connect to its web interface.
2. Go to Network → WAN.
3. If used LAN-to-WAN:
   • Select connection type Dynamic IP (DHCP).
   • Disable the DHCP server in the section LAN.

If used LAN-to-LAN:

• Disable the DHCP server.
• Change the IP address of Router2 so that it does not conflict with Router1 (for example, if Router1 has 192.168.1.1, set for Router2 192.168.1.2).
• Save the settings and reboot both devices.

Parameter	LAN-to-WAN	LAN-to-LAN
DHCP on Router2	Enabled (separate subnet)	Disabled
Router2 IP address	Any (receives from Router1)	Manual configuration (e.g. 192.168.1.2)
Accessing Router2 settings	Through its WAN IP	Via assigned IP (192.168.1.2)
Speed	Maximum	Maximum
Wi-Fi name	It can be changed	It is advisable to leave it as it is for Router1

4. How to avoid common connection errors

Even with proper setup, users still encounter problems. Here are the most common errors and their solutions:

1. No internet access after connecting

• 🔌 Check that the cable is connected to the correct ports (not in WAN Router1!).
• 🔄 Make sure DHCP is disabled on Router2 if you are using the following scheme: LAN-to-LAN.
• 📡 If you are using WDS, make sure the channels and encryption types match.

2. Devices do not see each other on the local network

• 🖥️ In the diagram LAN-to-WAN Devices from different subnets will not see each other. Use LAN-to-LAN.
• 🔒 Check that both modems are enabled AP Isolation (client isolation) - it needs to be turn off.

3. Wi-Fi works, but the speed is very slow.

• 📶 Speed ​​is always lower in WDS or Repeater mode. Try a cable.
• 🔄 If you are using 2.4 GHz, switch to 5 GHz (if both modems support it).
• 📡 Reduce the transmit power on Router1 if the signal is too strong and causing interference.

Why doesn't WDS work between modems of different brands?

Many manufacturers use non-standard WDS implementations. For example, TP-Link And ASUS They may not "see" each other in the list of available access points. The solution is to use universal repeater mode or a cable.

5. Setting up for popular modem models

Each brand has a unique interface, so we'll provide brief instructions for the most common devices.

TP-Link Archer C6 / C20:

• 🔧 WDS mode: Advanced Settings → Wireless Mode → WDS Bridge Setup.
• 🔄 Repeater mode: Operating mode → Signal amplifier.
• 🔌 Cascading connection: Disable DHCP in Network → LAN.

D-Link DIR-615 / DIR-825:

• 🔧 Bridge mode: Wi-Fi → Client Bridge (requires firmware not lower than 1.05).
• 🔄 Repeater: not supported on older revisions (WDS only).
• 🔌 For LAN-to-LAN, change the IP in Network → LAN.

Keenetic (any model):

• 🔧 Bridge mode: Wi-Fi → Access Point → Client Mode.
• 🔄 Repeater: Wi-Fi → Network Booster (firmware required) NDMS 3.0+).
• 🔌 Cascading connection: Disable DHCP in Home Network → Segment.

ASUS RT-N12 / RT-AC66U:

• 🔧 Bridge mode: Administration → Operating Mode → Repeater.
• 🔄 WDS support: Wireless Network → Bridge.
• 🔌 For LAN-to-LAN, change the IP in Local Network → IP Address.

⚠️ Attention: On models Keenetic with firmware NDMS 2.0 Repeater mode may not work reliably. Please update your firmware to the latest version via System → Update.

6. How to check that everything is working correctly

After setup, run a few tests to ensure the system is working properly:

1. Checking your internet connection:

• 🌐 Open your browser and try loading several websites (for example, google.com, yandex.ru).
• 📱 Connect your smartphone to the network and run a speed test (for example, via Speedtest).

2. Checking the local network:

• 🖥️ Make sure that devices connected to different modems can see each other (for example, you can ping: ping 192.168.1.100 from a computer connected to Router2).
• 📂 Check access to shared folders or printers.

3. Roaming check (for WDS/Repeater):

• 📡 Move between the coverage areas of Router1 and Router2, monitoring the signal strength.
• 🔄 Make sure your device automatically reconnects to a point with a better signal.

4. Problem diagnosis:

• 🛠️ If there is no internet, check your IP settings (ipconfig /all in the Windows command line).
• 🔍 If the devices can't see each other, check your modem's firewall settings.

7. Alternative solutions: when a second modem is not needed

If your goal is simply to extend your Wi-Fi coverage, you might want to consider specialized devices instead of a second modem:

• 📡 Mesh systems (For example, TP-Link Deco, ASUS ZenWiFi) - automatically manage roaming and ensure smooth transitions between points.
• 🔄 Wi-Fi repeaters (For example, Xiaomi Wi-Fi Repeater) - cheaper and easier to set up, but reduce speed.
• 🔌 Powerline adapters (For example, TP-Link TL-PA7010P) - transmit the Internet through electrical wiring, without requiring the laying of cables.

When to choose a second modem:

• 🏠 Need to create separate network (for example, for guests or a smart home).
• 🔧 Wanted additional ports for wired devices.
• 📶 Needed backup channel (for example, 5 GHz on the second modem, if the main one only works at 2.4 GHz).

FAQ: Frequently asked questions about connecting a second modem

Is it possible to connect a second modem without losing speed?

Yes, if you use cascade connection via cable (LAN-to-LAN or LAN-to-WAN). In WDS or Repeater modes, speed is always reduced by at least 30-50% due to traffic retransmission.

How can I make the second modem have its own Wi-Fi name?

In mode LAN-to-WAN or Repeater You can set any network name (SSID) for the second modem. In the mode WDS The network name is usually the same as the main modem, but some firmware (eg DD-WRT) allow you to change it.

Why don't devices automatically switch between modems?

Roaming between access points isn't ideal, especially on budget devices. Solutions:

• Set the same SSID, security type And password on both modems.
• Use different channels (e.g. 1 and 6 for 2.4 GHz) to reduce interference.
• Set the signal threshold for roaming (if the modem supports, for example, Keenetic with firmware NDMS 3.0+).

Is it possible to connect a second modem to a 4G modem?

Yes, but with some reservations:

• If the 4G modem has LAN port (For example, Huawei B525), connect the second modem to it via cable in mode LAN-to-WAN.
• If there are no ports, use the mode WDS or Repeater, but keep in mind that the speed will be limited by the capabilities of the 4G modem's Wi-Fi module.
• Some 4G modems (for example, ZTE MF286) do not support WDS - in this case, only a cable will help.

How do I reset the second modem if something goes wrong?

Most models have a button Reset (usually recessed into the case). Press it for 10-15 seconds with a pin – the modem will reset to factory settings. After this, you can set it up again. Attention: This will delete all custom settings including your Wi-Fi password!